2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96193We have studied atomic diffraction at normal incidence from an evanescent standing wave with a high resolution using velocity selective Raman transitions. We have observed up to 3 resolved orders of diffraction, which are well accounted for by a scalar diffraction theory. In our experiment the transverse coherence length of the source is greater than the period of the diffraction grating.8 pages, 4 figuresAtomic Physicstext